Nine people on board Royal Caribbean's Spectrum of the Seas, which was on a "cruise to nowhere" around the South China Sea, were identified as close contacts of a positive Covid case.

The nine close contacts were sent to a government quarantine center after the ship returned to port on January 5, according to a Hong Kong government statement.

Roughly 2,500 passengers and 1,200 crew were told to remain on the ship to undergo coronavirus testing.

Royal Caribbean said it was informed of the close contacts on January 4 and subsequently tested and isolated these passengers, according to a statement posted to the cruise line's Hong Kong Facebook page.

The nine close contacts reportedly tested negative via PCR tests.

To sail on Spectrum of the Seas, passengers and crew were required to be fully vaccinated, to file a health declaration and to test negative within 48 hours of boarding. Unvaccinated children had to show a negative test and fill out a health declaration.

In its statement, the Hong Kong government said it was concerned the nine people may have been in contact with a positive Omicron Covid case.

Hong Kong reported its first Omicron coronavirus case last week, following nearly three months without any local cases.

Hong Kong has kept up strict border regulations and quarantine rules for the duration of the pandemic. Omicron slipping through the net has led to the government to clamp down further on travel, banning flights from Australia, Canada, France, India, Pakistan, Philippines, the United States and the United Kingdom effective January 8.

Local Hong Kong restrictions have also been implemented, with indoor dining banned and entertainment venues such as cinemas, museums and bars and clubs temporarily shutting their doors.

Future cruises to nowhere are also off the table for now.

Story By | Francesca Street and Teele Rebane